Proximity sensor devices (also commonly called touch pads or touch sensor devices) are widely used in a variety of electronic systems. One type of proximity sensor is a capacitive proximity sensor device. A capacitive proximity sensor device typically includes a sensing region, often demarked by a surface, and uses capacitive technology to determine the presence, location and/or motion of one or more fingers, styli, and/or other objects. The capacitive proximity sensor device, together with finger(s) and/or other object(s), can be used to provide an input to the electronic system. For example, proximity sensor devices are used as input devices for larger computing systems, such as those found integral within notebook computers or peripheral to desktop computers. Capacitive proximity sensor devices are also used in smaller systems, including: handheld systems such as personal digital assistants (PDAs), remote controls, communication systems such as wireless telephones and text messaging systems. Increasingly, proximity sensor devices are used in media systems, such as CD, DVD, MP3, video or other media recorders or players.
A user generally operates a capacitive proximity sensor device by placing or moving one or more fingers, styli, and/or objects, near a sensing region of one or more sensors located on or in the sensor device. This creates a capacitive effect upon a carrier signal applied to the sensing region that can be detected and correlated to positional information (such as the position(s) or proximity or motion or presences or similar information) of the stimulus/stimuli with respect to the sensing region. This positional information can in turn be used to select, move, scroll, or manipulate any combination of text, graphics, cursors and highlighters, and/or any other indicator on a display screen. This positional information can also be used to enable the user to interact with an interface, such as to control volume, to adjust brightness, or to achieve any other purpose.
Although capacitance proximity sensor devices have been widely adopted for several years, sensor designers continue to look for ways to improve the sensors' functionality and effectiveness. In particular, designers continually strive to improve the accuracy and performance of the sensor device. Furthermore, designers continually strive to simplify the design and implementation of position sensor devices without increasing costs. Moreover, as sensor devices become increasingly in demand in various types of electronic devices, a need for a highly-flexible yet low cost and easy to implement sensor design arises. In particular, a continuing need exists for a sensor design scheme that is flexible enough for a variety of implementations and powerful enough to provide accurate capacitance sensing while remaining cost effective.
Accordingly, it is desirable to provide systems and methods for quickly, effectively and efficiently detecting a measurable capacitance. Other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.